Spinal tumours and metastatic spinal disease

• A spinal tumour is a neoplasm of the spinal cord, its meninges, or the bones and soft tissues around the spinal canal.
• About 15% of central nervous system tumours involve the spine, but primary spinal neoplasms are rare (about 2 to 4% of all central nervous system tumours), and roughly 65% of these are intradural and extramedullary, most often meningiomas and schwannomas.^[2]
• The commonest intramedullary tumours are ependymoma and astrocytoma; ependymoma is usually slow growing and well circumscribed, while astrocytoma is more infiltrative.
• Metastatic disease is the commonest spinal tumour in adults: about 10% of people with cancer develop symptomatic spinal metastatic disease, and 5 to 10% of those need an operation.^[4]
• Metastatic spinal cord compression is an oncological emergency: recognise it early, confirm it with whole-spine MRI, and treat it promptly with immobilisation, dexamethasone, radiotherapy and, in selected patients, urgent surgery.^[1]
• Radiation of the spinal cord is limited by the risk of myelopathy, so doses are capped near 50 to 54 Gy in conventional fractionation for most tumours, and metastatic disease is often treated with a single 8 Gy fraction.^[1][3]

By the end of this page you should be able to:

1. Classify spinal tumours by anatomical compartment and predict which tumours belong where.
2. Recognise the red flags of spinal metastases and metastatic spinal cord compression and name the oncological emergency pathway.
3. Interpret a spinal MRI for a tumour, including the usual signal pattern of meningioma and schwannoma.
4. Explain why 16 mg of oral dexamethasone is given for cord compression, and how the dose is tapered.
5. Outline the management of extradural metastases: immobilisation, stability scoring, radiotherapy fractionation, bisphosphonates and surgery.
6. Outline the principles of treating primary intradural tumours: gross total resection, watch and wait after complete resection of grade II ependymoma, and postoperative radiotherapy.
7. Counsel a patient on prognosis and on the possibility of recurrence with long-term MRI follow-up.

Spinal tumours are rare. Reported incidence of primary spinal neoplasia is about 1 case per million population per year, and primary spinal neoplasms are a small fraction of all central nervous system tumours.^[3] They are usefully grouped in three compartments, because the compartment predicts the likely histology, the imaging appearance and the surgical approach.

Most primary spinal tumours are benign. Malignant behaviour in this context is usually either an aggressive primary tumour (for example an anaplastic ependymoma) or metastatic disease from elsewhere. A useful working rule is that a solitary intradural extramedullary mass in an adult is a meningioma or a schwannoma until proven otherwise, whereas a destructive vertebral lesion is usually metastatic.

References: primary spinal neoplasms account for roughly 2 to 4% of central nervous system tumours, and spinal tumours overall for around 15%.^[2]

• Primary spinal tumours are uncommon; metastatic spinal disease is common.
• An estimated 10% of people with cancer develop symptomatic spinal metastatic disease; of those, up to 50% need treatment and 5 to 10% need an operation.^[4]
• In a large pooled series of 61 studies and 22,335 patients operated on for spinal metastatic disease, the commonest primary tumour sources were lung (about 31%), kidney (about 18%), breast (about 16%) and prostate (about 14%), and surgery was done mainly for progressive neurological dysfunction (80%), intractable pain (33%) and spinal instability (20%).^[4]
• About 65% of primary spinal neoplasms are intradural extramedullary, most often meningiomas, schwannomas and neurofibromas. Meningiomas are about 2.3 times more common in females than males and their incidence rises strongly after the age of 65 years.^[2][6]
• Ependymal tumours account for about 1.8% of all primary central nervous system tumours (annual incidence about 0.43 per 100,000 population) and occur more in males (ratio 1.3 to 1). They make up about 18% of all spinal cord tumours.^[5][3]
• Spinal meningiomas are much rarer than intracranial meningiomas but follow the same principles.^[6]

• Metastases. Reflect the underlying primary cancer. Lung, kidney, breast and prostate are the commonest sources in surgical series.^[4]
• Meningioma. Female sex and older age are associated; ionising radiation is a recognised risk; type 2 neurofibromatosis is the commonest genetic association and patients are more likely to have multiple or high-grade meningiomas.^[6]
• Schwannoma. May be sporadic or part of neurofibromatosis type 2 or schwannomatosis.
• Ependymoma. Often sporadic; spinal ependymomas are more common in adults than children.^[5]
• Astrocytoma. A primary glial tumour of the cord; not classified as a separate entity from cerebral glioma, so molecular findings and management largely follow the cranial disease.^[3]
• There is no known modifiable risk factor for most primary spinal tumours.

Everything the patient feels follows from the anatomy of the spinal canal: a bony tube with a narrow margin of space around the cord, poor in collateral blood supply, and easily destabilised by bone destruction.

• Compression of the cord or cauda equina raises venous pressure, impairs axonal conduction and, if untreated, produces ischaemia and infarction. Back pain comes from periosteal and ligamentous stretch and from nerve-root involvement.
• Mechanical instability follows destruction of bone by metastases: movement produces pain and further neural injury.
• Neurological deficit is usually ascending: pain and sensory change first, then motor weakness and gait disturbance, finally bladder and bowel dysfunction.
• Pain may be local (at the level of the lesion), radicular (shooting along a dermatome), or mechanical (worse on standing, sitting or moving, better at rest).
• Symptom onset can be rapid in metastatic disease, which is why cord compression is treated as an emergency; in primary tumours it is usually slow, sometimes over months or years, which is why diagnosis is often delayed.^[2][4]

A spinal tumour should be considered when back pain has particular characteristics, or when neurological or constitutional symptoms appear. The NICE guideline on spinal metastases and metastatic spinal cord compression lists factors that suggest the diagnosis; these are worth learning verbatim.^[1]

Ask about cancer history (including a cancer treated years ago), weight loss, night pain, and change with activity. Ask about numbness, weakness, falls, and changes in walking. Ask specifically about bladder and bowel control. In a patient with known cancer, new severe back pain is metastatic disease until excluded.^[1]

Look for a sensory level, increased or absent reflexes, extensor plantar responses and a single or multiple myotomal weakness. Check gait and the ability to walk unaided. Palpate the spine for localised tenderness. In the primary tumour group there may be little to find early; an intramedullary lesion can present with dissociated sensory loss and a syrinx. A clear and reproducible sensory level makes a cord lesion likely.

• Meningioma and schwannoma usually present with slowly progressive pain, weakness or sensory change. Schwannomas can cause radicular pain and may show hyperintensity on T2-weighted MRI; a diagnosis of schwannoma is favoured when an intradural extramedullary tumour shows T2 hyperintensity without a dural tail sign. Meningioma shows more homogeneous, moderate contrast enhancement and the dural tail sign.^[2]
• Ependymoma often causes dull central back pain, sometimes with syrinx symptoms, and may show a "cap" of low T2 signal from haemosiderin at the poles. It is more frequent in adults.^[5]
• Astrocytoma tends to be longer, more infiltrative, and harder to resect completely; presentation is often with a progressive myelopathy.
• Metastases present with pain first, then neurological deficit; pain may be severe, progressive, mechanical or night-time, and weight loss or fever may accompany systemic cancer.^[1]

Not every progressive myelopathy is a tumour. The main alternatives, and the features that separate them, are:

Contrast-enhanced MRI is the investigation of choice for spinal tumours; CT is reserved for when MRI is contraindicated, and plain X-ray should not be used to diagnose or exclude spinal metastases or cord compression.^[1] For suspected primary tumours, MRI separates the compartment and the tissue type with good accuracy; in one cross-sectional study, MRI had a positive predictive value of 99%, negative predictive value of 95.5% and diagnostic accuracy of 97.7% against histology.^[2]

The NICE guideline for suspected metastatic disease recommends a protocol that is sensible for any tumour work-up:^[1]

• a sagittal T1 and/or STIR sequence of the whole spine to identify metastases;
• sagittal T2-weighted sequences to show the level and degree of compression of the cord or cauda equina by a soft-tissue mass, to assess possible cord compression and to detect lesions within the cord itself;
• supplementary axial images through every significant abnormality on the sagittal scan.

For a suspected primary intradural extramedullary tumour, the MRI features in the table below separate the two commonest types.^[2]

In intramedullary disease, ependymomas are usually circumscribed with distinct borders and a haemosiderin cap; astrocytomas are longer and less clearly demarcated.^[5]

• Suspected metastatic cord compression (neurological signs or symptoms): MRI within 24 hours at the local hospital; urgent overnight imaging only if treatment depends on an immediate diagnosis.^[1]
• Suspected spinal metastases without cord compression: MRI within 1 week.^[1]
• After a primary intradural operation, postoperative MRI is used to confirm the extent of resection.^[5][6]

Plain radiography and myelography are not routine; CT can be reconstructed in three planes to assess stability and to plan vertebroplasty, kyphoplasty or spinal surgery.^[1]

• Blood tests: full blood count, coagulation, renal function, calcium, and glucose if steroids are given; tumour markers and cancer staging as appropriate.
• Histology is the definitive diagnosis. In a small number of metastatic patients with an unknown primary, a biopsy may be needed before planning.
• Preoperative assessment of ambulation, performance status (Karnofsky or ECOG), comorbidity and frailty matter, because they predict surgical outcomes in spinal metastatic disease.^[4]

Primary tumours are diagnosed histologically and graded by the World Health Organization classification. For clinical practice, two points from the 2018 European Association of Neuro-Oncology guideline on ependymal tumours are useful on the spine:^[5]

• Spinal cord ependymomas are distinct from astrocytomas and behave better: gross total resection is the aim, and radiotherapy is reserved for incompletely resected or anaplastic (WHO grade III) tumours.
• Myxopapillary ependymoma is located in the conus, cauda equina and filum terminale and is now graded WHO grade 2.

For meningiomas, the 2021 European Association of Neuro-Oncology guideline (covering diagnosis and management) sets out the current classification, molecular markers and the observation-versus-surgery algorithm.^[6]

For metastatic disease, two validated tools are worth knowing, although they support rather than replace clinical judgement:^[1]

• Spinal Instability Neoplastic Score (SINS): a structured assessment of stability, used with clinical assessment to decide on immobilisation and surgical stabilisation. ^[1]
• Revised Tokuhashi score: a prognostic score, used with comorbidity and performance status to inform treatment discussions.

For metastatic disease there are no fixed dose or scan intervals beyond the guideline recommendations quoted here; the decision is taken in a multidisciplinary team that includes oncology, palliative care, radiology and spinal surgery.^[1]

Treat suspected metastatic spinal cord compression as an oncological emergency.^[1]

1. Assess and document neurological function, pain and stability.
2. Immobilise the spine without delay, including for transfer to hospital, when there are neurological symptoms or signs suggesting spinal instability; consider immobilisation for moderate to severe pain on movement. Nurse the immobilised patient supine (flat or partially elevated) to minimise loading of the spine.^[1]
3. Give 16 mg of oral dexamethasone (or the equivalent parenteral dose) as soon as possible if there are neurological symptoms or signs of cord compression; continue 16 mg daily while the patient awaits surgery or radiotherapy; reduce gradually after surgery or at the start of radiotherapy, and stop according to the adrenal insufficiency guidance.^[1] (See the NICE NG234 corticosteroid recommendations; this is the current evidence-based dose.)
4. Arrange MRI of the whole spine within 24 hours locally.^[1]
5. Contact the metastatic cord compression coordinator immediately; a designated specialist service should be available at all times.^[1]
6. Start analgesia: non-opioid and opioid analgesia, individually or in combination, plus specialist pain or palliative care if pain is severe or limiting.^[1]
7. Do not use bisphosphonates or routine corticosteroids unless the guideline indications are met (see below).^[1]

If MRI rules out spinal metastases or cord compression after steroids have been given, stop the dexamethasone.^[1]

• Neurological symptoms or signs of cord compression: 16 mg oral dexamethasone (or equivalent parenteral dose) as soon as possible, then 16 mg daily while awaiting surgery or radiotherapy; taper after surgery or at the start of radiotherapy.
• No neurological symptoms or signs: do not routinely offer corticosteroids; consider them if there is severe pain or a haematological malignancy. ^[1]
• For spinal metastases or cord compression from a haematological malignancy: 16 mg oral dexamethasone (or equivalent parenteral dose) as soon as possible, then further corticosteroid treatment in discussion with the haematology multidisciplinary team.
• Seek specialist haematological advice before starting corticosteroids when lymphoma or myeloma is suspected but not confirmed.
• For patients taking corticosteroids: monitor blood glucose and offer proton pump inhibitor acid suppression.

• Analgesia should be prompt and individualised; review after starting or changing the plan.
• Bisphosphonates reduce pain and the risk of vertebral fracture or collapse in myeloma and breast cancer with spinal involvement.
• Bisphosphonates reduce pain in prostate cancer only if conventional analgesia fails.
• Do not use bisphosphonates for spinal pain from other tumour types, or with the intention of preventing cord compression except in a trial.
• Denosumab for bone metastases from breast cancer and from solid tumours other than prostate follows the relevant technology appraisal.
• Do not stop analgesia while waiting for imaging or treatment.

Surgery is indicated for decompression of the neural elements, restoration of biomechanical stability and relief of intractable pain.^[4] The AO Spine Knowledge Forum Tumor group gives a strong recommendation for urgent surgical decompression in patients who have neurological deficits from solid spinal metastatic disease that have produced loss of ambulation, in the absence of medical and oncological contraindications.^[4]

Practical surgical points drawn from the current evidence:^[4]

• Posterior approaches dominate surgical practice (about 84%), with decompression with or without fusion used in roughly 80% of operated patients. ^[4]
• Preoperative systemic status (age over 60, medical comorbidity, performance, nutrition, ambulation) predicts outcome, so fitness assessment is part of the surgical decision. ^[4]
• When surgery is not feasible or not chosen, radiotherapy is the main alternative.

For primary tumours, the principle is maximal safe resection:

• Intradural extramedullary tumours (meningioma, schwannoma): total microsurgical resection with decompression of the canal is the gold standard.^[2] For spinal meningioma, the same principles as for intracranial meningioma apply and most data support aiming for gross total resection even in elderly patients, with recurrence rates of 1.3 to 14.7% in surgical series.^[6] For spinal schwannoma, most tumours are resectable with low morbidity; functional outcome is better with lower tumour occupancy on MRI.^[2]
• Ependymoma: gross total resection is the goal and gives the best functional outcome; small tumour size and good preoperative neurological status favour this. Postoperative radiotherapy (45 to 54 Gy) is recommended for anaplastic (WHO grade III) ependymoma regardless of resection extent, and for WHO grade II disease after incomplete resection; after gross total resection of a WHO grade II tumour a watch-and-wait strategy is recommended.^[5]
• Myxopapillary ependymoma: gross total resection is recommended where possible; postoperative radiotherapy with at least 50 Gy is recommended after incomplete resection, and studies have shown improved local control and progression-free survival with higher doses.^[5]
• Astrocytoma: surgery is undertaken for diagnosis, control and preservation of function; combining surgery with radiotherapy gave significantly better survival than radiotherapy alone in one series, although high-grade disease carries a poor prognosis despite treatment. Radiotherapy doses for spinal astrocytoma range from 45 to 54 Gy, or up to 59.4 Gy below the conus medullaris according to histology.^[3]

• Postoperative MRI to confirm the extent of resection.^[5][6]
• Ependymoma: craniospinal MRI and cerebrospinal fluid cytology after surgery because of the risk of dissemination, and long-term follow-up because relapse may be late and silent.^[5]
• Meningioma: surveillance by MRI; recurrence after surgery is the rule only when resection is incomplete.^[6]

Radiotherapy is central to both metastatic and primary spinal disease, but doses are constrained by the risk of myelopathy.

For metastatic disease (NICE NG234):^[1]

• Painful spinal metastases without cord compression: offer 8 Gy single fraction, even if the patient is paralysed; consider stereotactic ablative body radiotherapy for a good-prognosis patient or for oligometastases (up to 3 discrete metastases anywhere) with spinal involvement. ^[1]
• Metastatic cord compression not suitable for surgery: urgent radiotherapy within 24 hours, unless the patient has had complete tetraplegia or paraplegia for over 2 weeks with controlled pain, or a poor overall prognosis. ^[1]
• For cord compression requiring radiotherapy: 8 Gy single fraction unless the patient is at high risk of side effects, in which case use multiple fractions; high-risk reasons include a large treatment field or previous radiotherapy. ^[1]
• Asymptomatic spinal metastases: radiotherapy only in a trial to prevent cord compression, or as part of treatment for oligometastases, or when there are radiological signs of impending compression by an epidural or intradural tumour. ^[1]

For primary spinal tumours (fractionated conventionally, 1.8 Gy per fraction), the current evidence-based ranges are:^[3][5][6]

• Ependymoma: 45 to 54 Gy postoperatively after incomplete resection of a WHO grade II tumour, and 45 to 54 Gy regardless of resection for WHO grade III (anaplastic) tumour.
• Myxopapillary ependymoma: postoperative radiotherapy is associated with improved control at doses of at least 50 Gy, with good tolerance.
• Meningioma: 50.4 to 54 Gy in 1.8 Gy fractions if adjuvant radiotherapy is used; radiotherapy is associated with reduced mortality in higher-grade or large tumours. ^[6]
• Astrocytoma: 45 to 54 Gy, up to 59.4 Gy below the conus medullaris according to histology.

Safety limits that matter: myelopathy is the feared complication. By QUANTEC estimates, the risk of myelopathy is about 0.2% at 50 Gy, about 6% at 60 Gy and about 50% at 69 Gy (all in 2 Gy equivalents). Early myelopathy (2 to 4 months after radiotherapy) is often self-limiting and presents with Lhermitte sign; late myelopathy is permanent. Conventional cord constraints outside the spine are often set at 45 Gy; spinal tumour treatments push to 54 Gy with an estimated 1 to 2% myelopathy risk. Treatment is with corticosteroids, and the aim is to avoid toxicity first.^[3]

• Neurological deterioration or paralysis if metastatic cord compression is untreated: an oncological emergency.

• Surgical complications in metastatic disease include infection, hardware failure, transfusion and venous thromboembolism; performance status, nutrition and comorbidity predict risk.^[4]

• Radiation myelopathy: early (Lhermitte sign, self-limiting) or late and permanent; corticosteroids are used but prevention matters most.^[3]

• Recurrence of meningioma or ependymoma may occur years after surgery.

• Secondary effects of high-dose steroids: hyperglycaemia, infection and gastro-intestinal bleeding, hence glucose monitoring and proton pump inhibitor cover.^[1]

• Ependymomas are the more favourable intramedullary group: gross total resection is associated with prolonged survival; in one ependymoma series the 5- and 10-year overall survival rates were 86.1% and 81%, and spinal ependymomas have a better prognosis than spinal astrocytomas.^[5] Incompletely resected WHO grade II tumour treated with radiotherapy had median progression-free survival of 96 months versus 48 months with surgery alone.^[5]
• Astrocytomas carry a poor prognosis in most series; high-grade disease in particular has a poor outcome despite resection and radiotherapy.^[3]
• Meningiomas are usually curable by surgery. Recurrence rates of 1.3 to 14.7% are reported after resection, and outcome is predicted by the extent of resection.^[6]
• Metastatic disease prognosis depends on the primary tumour, systemic control and initial neurological status; preoperative neurological deficit and visceral disease worsen outcome, while good performance status predicts benefit from surgery.^[4]
• Myelopathy risk from radiotherapy rises steeply above 50 Gy (about 0.2% at 50 Gy, about 6% at 60 Gy and about 50% at 69 Gy in 2 Gy equivalents).^[3]

• There is no population screening for spinal tumours.
• Primary prevention is limited to the usual avoidance of unnecessary radiation and, for neurofibromatosis type 2 families, surveillance by genetic testing and MRI.
• For metastatic disease, prevention is about early recognition: cancer patients with new or progressive back pain, night pain, neurological symptoms or signs of cord compression must be assessed promptly, because treatment before neurological loss gives the best outcome.^[1]

• Children. Intramedullary tumours in children are usually astrocytomas or ependymomas, and radiotherapy should be considered in anaplastic or high-risk disease with doses lowered for very young children; craniospinal irradiation is used only for disseminated ependymoma.^[5]
• Older adults. Spinal meningiomas in the elderly are still safely resectable in most cases, and observation, radiosurgery or hypofractionated radiotherapy may be preferred if the patient is frail.^[6]
• Pregnancy. Meningioma may grow during pregnancy under hormonal influence. Management decisions should balance maternal neurological need against fetal safety, and require multidisciplinary discussion.
• Low-resource settings. MRI is not available everywhere; clinical red flags (progressive nocturnal or mechanical pain in a cancer patient, a sensory level, bladder or bowel disturbance) should prompt urgent referral. If further imaging is impossible, treat on the basis of the best clinical and whatever structural assessment is available, and prioritise analgesia, immobilisation and access to radiotherapy.

• A focused neurological examination and recognition of the red flags is the single most valuable intervention and costs nothing.
• Where MRI is unavailable, plain CT can confirm vertebral destruction or a large mass, and myelography may be used rarely by specialist centres.
• If radiotherapy or spinal surgery are unavailable locally, transfer the patient to a centre that can offer them within the therapeutic window; for cord compression, delay worsens outcome.
• Systemic therapy, oral dexamethasone and opioids can be used while transfer is arranged, and community nursing with home equipment supports safe discharge.^[1]

• Primary spinal tumours are rare (about 2 to 4% of central nervous system tumours) and mostly benign; metastatic disease is the commonest spinal tumour in adults.
• About 10% of people with cancer develop symptomatic spinal metastatic disease, and 5 to 10% of them need surgery. The commonest sources are lung, kidney, breast and prostate.^[4]
• About 65% of primary spinal neoplasms are intradural extramedullary: meningioma and schwannoma dominate, and they are usually slow growing, benign and surgically resectable.^[2]
• Intramedullary tumours are ependymoma and astrocytoma. Gross total resection is the goal for ependymoma; anaplastic or incompletely resected ependymoma deserves postoperative radiotherapy at 45 to 54 Gy.^[5]
• Ependymomas are circumscribed intramedullary tumours and may show a haemosiderin cap; astrocytomas are more infiltrative.^[5]
• Spinal cord compression from metastatic disease is an oncological emergency: recognise it by red-flag back pain and by bladder, bowel or gait disturbance, confirm with whole-spine MRI within 24 hours, and treat with immobilisation and 16 mg of dexamethasone then urgent surgery or radiotherapy.^[1]
• Immobilise for neurological symptoms or signs suggesting instability, or for moderate to severe pain on movement; nurse supine.^[1]
• Dexamethasone dose for cord compression with neurological signs: 16 mg oral (or equivalent parenteral) as soon as possible, 16 mg daily while awaiting surgery or radiotherapy, then taper. Steroids are not routine without neurological signs except for severe pain or a haematological malignancy.^[1]
• MRI of the whole spine should use sagittal T1/STIR plus sagittal T2 sequences, with axial images through every abnormality; do not use plain X-ray. CT is used if MRI is contraindicated.^[1]
• For metastatic disease, the radiotherapy standard is 8 Gy single fraction for painful metastases and for cord compression when surgery is not suitable; multiple fractions for high-risk patients; urgent radiotherapy within 24 hours.^[1]
• For painful metastatic disease without cord compression, offer 8 Gy single fraction, and consider stereotactic ablative body radiotherapy for good-prognosis or oligometastatic patients.^[1]
• Two stability and prognosis tools worth knowing: the Spinal Instability Neoplastic Score and the revised Tokuhashi score.^[1]
• The spinal cord tolerates only about 54 Gy in conventional fractionation; above this myelopathy risk rises steeply.^[3]
• Bisphosphonates are evidence-based for myeloma and breast (pain and fracture) and for prostate pain on analgesic failure only; denosumab follows technology appraisal for breast and non-prostate solid tumours.^[1]
• Spinal meningiomas follow intracranial principles: surgery is primary, gross total resection is the aim, and adjuvant radiotherapy at 50.4 to 54 Gy is used for grade 2, 3 or large residual tumours.^[6]
• Long-term MRI follow-up is required after resection of ependymoma and meningioma because recurrence may be late.
• Red flags for metastatic disease: severe, progressive, mechanical or night-time back pain, weight loss and any neurological or bladder or bowel change in a patient with a history of cancer.^[1]

Spinal tumours relate to the topics that cover the same territory: brain tumours and central nervous system neoplasms, neuro-oncology, back pain and spinal stenosis, neuropathic pain, cancer pain management, oncological emergencies, neuro-imaging, and palliative care. See also the concepts of spinal instability, performance status and radiotherapy.